/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.cep.utils;

import org.apache.flink.cep.Event;
import org.apache.flink.cep.EventComparator;
import org.apache.flink.cep.functions.PatternProcessFunction;
import org.apache.flink.cep.nfa.NFA;
import org.apache.flink.cep.nfa.aftermatch.AfterMatchSkipStrategy;
import org.apache.flink.cep.nfa.compiler.NFACompiler;
import org.apache.flink.cep.operator.CepOperator;
import org.apache.flink.util.Collector;
import org.apache.flink.util.OutputTag;

import java.util.List;
import java.util.Map;

/**
 * Test builder for cep operator that accepts {@link Event} as input elements.
 *
 * @param <OUT> type of output elements
 */
public class CepOperatorBuilder<OUT> {

	private final boolean isProcessingTime;
	private final NFACompiler.NFAFactory<Event> nfaFactory;
	private final EventComparator<Event> comparator;
	private final AfterMatchSkipStrategy skipStrategy;
	private final PatternProcessFunction<Event, OUT> function;
	private final OutputTag<Event> lateDataOutputTag;

	public static CepOperatorBuilder<Map<String, List<Event>>> createOperatorForNFA(NFA<Event> nfa) {
		return new CepOperatorBuilder<>(
			true,
			new NFACompiler.NFAFactory<Event>() {
				@Override
				public NFA<Event> createNFA() {
					return nfa;
				}
			},
			null,
			null,
			new PatternProcessFunction<Event, Map<String, List<Event>>>() {
				private static final long serialVersionUID = -7143807777582726991L;

				@Override
				public void processMatch(
					Map<String, List<Event>> match,
					Context ctx,
					Collector<Map<String, List<Event>>> out) throws Exception {
					out.collect(match);
				}
			},
			null);
	}

	public static CepOperatorBuilder<Map<String, List<Event>>> createOperatorForNFAFactory(NFACompiler.NFAFactory<Event> nfaFactory) {
		return new CepOperatorBuilder<>(
			true,
			nfaFactory,
			null,
			null,
			new PatternProcessFunction<Event, Map<String, List<Event>>>() {
				private static final long serialVersionUID = -7143807777582726991L;

				@Override
				public void processMatch(
					Map<String, List<Event>> match,
					Context ctx,
					Collector<Map<String, List<Event>>> out) throws Exception {
					out.collect(match);
				}
			},
			null);
	}

	private CepOperatorBuilder(
		boolean isProcessingTime,
		NFACompiler.NFAFactory<Event> nfaFactory,
		EventComparator<Event> comparator,
		AfterMatchSkipStrategy skipStrategy,
		PatternProcessFunction<Event, OUT> processFunction,
		OutputTag<Event> lateDataOutputTag) {
		this.isProcessingTime = isProcessingTime;
		this.nfaFactory = nfaFactory;
		this.comparator = comparator;
		this.skipStrategy = skipStrategy;
		function = processFunction;
		this.lateDataOutputTag = lateDataOutputTag;
	}

	public CepOperatorBuilder<OUT> inProcessingTime() {
		return new CepOperatorBuilder<>(
			true,
			nfaFactory,
			comparator,
			skipStrategy,
			function,
			lateDataOutputTag);
	}

	public CepOperatorBuilder<OUT> inEventTime() {
		return new CepOperatorBuilder<>(
			false,
			nfaFactory,
			comparator,
			skipStrategy,
			function,
			lateDataOutputTag);
	}

	public CepOperatorBuilder<OUT> withComparator(EventComparator<Event> comparator) {
		return new CepOperatorBuilder<>(
			false,
			nfaFactory,
			comparator,
			skipStrategy,
			function,
			lateDataOutputTag);
	}

	public CepOperatorBuilder<OUT> withSkipStrategy(AfterMatchSkipStrategy skipStrategy) {
		return new CepOperatorBuilder<>(
			false,
			nfaFactory,
			comparator,
			skipStrategy,
			function,
			lateDataOutputTag);
	}

	public CepOperatorBuilder<OUT> withLateDataOutputTag(OutputTag<Event> lateDataOutputTag) {
		return new CepOperatorBuilder<>(
			false,
			nfaFactory,
			comparator,
			skipStrategy,
			function,
			lateDataOutputTag);
	}

	public CepOperatorBuilder<OUT> withNFA(NFA<Event> nfa) {
		return new CepOperatorBuilder<>(
			false,
			new NFACompiler.NFAFactory<Event>() {
				@Override
				public NFA<Event> createNFA() {
					return nfa;
				}
			},
			comparator,
			skipStrategy,
			function,
			lateDataOutputTag);
	}

	public <T> CepOperatorBuilder<T> withFunction(PatternProcessFunction<Event, T> processFunction) {
		return new CepOperatorBuilder<>(
			isProcessingTime,
			nfaFactory,
			comparator,
			skipStrategy,
			processFunction,
			lateDataOutputTag);
	}

	public <K> CepOperator<Event, K, OUT> build() {
		return new CepOperator<>(Event.createTypeSerializer(),
			isProcessingTime,
			nfaFactory,
			comparator,
			skipStrategy,
			function,
			lateDataOutputTag);
	}
}
